The effects of progesterone treatment on nuchal translucency in women with threatened miscarriage.

This study aims to investigate the effects of progesterone on the possible changes in nuchal translucency (NT) levels for patients diagnosed with threatened miscarriage. The study group was composed of 125 patients diagnosed with threatened miscarriage and taking 400 mg/day micronized orally progesterone at least for two weeks, the control group was composed of 160 healthy pregnant women not taking any progesterone. Crown rump length (CRL) NT thickness, Pregnancy-associated plasma protein-A (PAPP-A), free beta human chorionic gonadotropin (Beta-HCG) levels of patients were measured for assessment of aneuploidy risk. Both of the groups were divided into four subgroups to determine the relationship between thickness of NT and progesterone use for specific CRL measurements. CRL in the first, second, third and fourth group was 45-55 mm, 55-65 mm, 65-75 mm, 75-84 mm, respectively. The two groups were age and BMI matched. In all groups of CRL there were no significant difference in Mom levels of NT thickness, PAPP-A and free Beta-HCG between the study and control groups. There havent been any relation between NT thickness and progesterone use.IMPACT STATEMENTWhat is already known about this subject? Recently some studies have claimed that progesterone use might have caused atypical blood flow pattern on foetal circulation, which could possibly increase NT. If the NT thickness is affected by the use of progesterone, then the false positive rate of detecting Down Syndrome screening tests would increase.What the results of this study add? In this study we did not found any relation between NT thickness and progesterone use.What the implications are of these findings for clinical practice and/or further research? Using orally progesterone due to threatened miscarriage do not change NT thickness levels. Further studies have to be done with a large number of participants.

Effects of exogenous progesterone on fetal nuchal translucency: an observational prospective study.

OBJECTIVE: Nuchal translucency (NT) seen ultrasonographically at 11-14 weeks' gestation is a sensitive marker for Down syndrome. Despite its important role for Down syndrome screening, its use is still considered controversial due to high false-positive rates. We speculated that progesterone could lead to abnormal blood flow patterns and, subsequently, to increased NT. Our primary endpoint was to evaluate the effects of exogenous progesterone on NT thickness compared to controls. The secondary endpoint was to evaluate these effects in a subgroup at low risk for fetal aneuploidies, identifying the strongest factors influencing NT variation. The tertiary endpoint was to evaluate, within the treatment group, if there is any difference in NT according to the type of progesterone administered, route of administration, and dose regimen. STUDY DESIGN: All women who came to measure NT at 11-14 weeks' gestation (crown-rump length between 45-84 mm) were considered eligible. We divided patients into 2 groups: women receiving exogenous progesterone and controls. Afterwards, 3 NT scans were performed for each case, and the largest value, accurate to 2 decimal points, was recorded. RESULTS: In all, 3716 women were enrolled and analyzed. In a crude analysis, NT (P < .05) increased in the exogenous progesterone group. The same results were obtained in the low-risk group (P < .05). The factorial analysis of variance model confirmed a correlation between altered NT and gestational age (P < .0001) and progesterone exposure (P < .05). The characteristics of treatment (route, formulation, dose) were examined separately and no statistically significant differences among the subgroups were observed. CONCLUSION: Exogenous progesterone increases NT.